Announcement

Collapse
No announcement yet.

Viewsonic vx2235wm colors washed out after power board recapping

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

    Viewsonic vx2235wm colors washed out after power board recapping

    Hello everyone,

    I am experiencing a weird problem with my monitor in that after changing faulty caps on the power board (pictured) because my monitor was turning off , i reassembled and it power up but this time with the colors washed out when in Windows. I posted a picture of the actual monitor and the same image on my LG monitor for comparison purposes

    When opening up the menu, colors are fine it is only when entering into Windows.

    I read other posts and someone suggested to take the Voltage readings on the TCon board, here they are with monitor turned on:

    VDD - found AVDD1 12.80V
    AVDO - 23.42V
    VGH - 24.6V
    VGG - -6.98V

    I think they measure OK. I checked the ribbon cables (there are 2) each pin of both end of the connectors and I get a good connection - this was a long task!

    Also did a monitor reset which is Memory Recall on this monitor, nothing changed, still washed out display.

    So now, I really don't know where to look to get the vibrant colors I had. Any help would be greatly appreciated! Many thanks!
    Attached Files
    Last edited by rddube; 12-18-2017, 10:06 PM.

    #2
    Re: Viewsonic vx2235wm colors washed out after power board recapping

    It looks like the GAMMA ref Voltages are wrong.
    Check VGMA1~14 to see what you get.
    You did not touch the T-CON bd. at all, right?
    Never stop learning
    Basic LCD TV and Monitor troubleshooting guides.
    http://www.badcaps.net/forum/showthr...956#post305956

    Voltage Regulator (LDO) testing:
    http://www.badcaps.net/forum/showthr...999#post300999

    Inverter testing using old CFL:
    http://www.badcaps.net/forum/showthr...er+testing+cfl

    Tear down pictures : Hit the ">" Show Albums and stories" on the left side
    http://s807.photobucket.com/user/budm/library/

    TV Factory reset codes listing:
    http://www.badcaps.net/forum/showthread.php?t=24809

    Comment


      #3
      Re: Viewsonic vx2235wm colors washed out after power board recapping

      Hi Budm,

      Thank you so much for your reply! Ok, I think I might have taken these voltages wrong, not sure?

      I uploaded another copy of the right side of the TCON board to show where I measured voltages, as the labels were not exactly as mentioned in my post. Please bear with me I am a newbie in this area (I know a little electronics and can solder desolder pretty well, but that's about it).

      Now looking over my voltages:

      VDD - found AVDD1 12.80V - OK, this is good
      AVDO - 23.42V - I can't seem to find where I got this measurement?
      VGH - 24.6V - you can see circled VGH1 on the attached picture
      VGL - -6.98V - you can see circled VGL1 on attached picture - on original post, I made typo, not VGG but VGL.

      Can't seem to find VGMA1 - 14 anywhere on the TCON board - can you point it out for me?

      Also, no I did not touch the TCON board, just the power supply board changed bulging CAPS and on the power supply board, when powered up, I get a clean 5.2V and 13.8 V.

      I should mention that when I powered it back on, it looked fine, but when I did a memory recall (which is factory reset) it came back with the washed out colours.

      One last thing when working on it, I noticed on the main board a ceramic cap which seem to have gotten loose (maybe because of opening the case). I resoldered it back to its place near the right connector. But only after it had given me the washed out colors, so I don't think it is related, but then again, what do I know.

      Many thanks for your help!
      Attached Files

      Comment


        #4
        Re: Viewsonic vx2235wm colors washed out after power board recapping

        Just to make sure I am clear about that little ceramic capacitor, here it is the circled in red. After resoldering it, it reads approx. 85.2uf, just like the bigger ceramic capacitor to its right with which it it connected in parallel.

        Tks.
        Attached Files

        Comment


          #5
          Re: Viewsonic vx2235wm colors washed out after power board recapping

          Originally posted by rddube View Post
          AVDO - 23.42V - I can't seem to find where I got this measurement?
          Most likely test point AVDD1? Looks right to me anyways.

          Originally posted by rddube View Post
          Can't seem to find VGMA1 - 14 anywhere on the TCON board - can you point it out for me?
          Visible in the left center of this picture you uploaded:
          https://www.badcaps.net/forum/attach...9&d=1513655805
          Careful not to poke your eyes on them test points.

          By the way, what replacement capacitors did you end up using? I see a bright orange one on the PSU and I'm pretty sure that's not original. It also doesn't look like a known good Japanese brand to me. Hence the reason I ask. You should recap this with genuine Japanese low ESR capacitors from either Digikey, Mouser, or Badcaps.net store. Anything from eBay, Amazon, and Ali Express is very likely to be counterfeit or no-name Chinese junk. Slim chance that this is the reason for the washed-out colors, but still worth changing those caps just in case. Besides, your repair will actually last a very long time if you do use good quality Japanese caps. With cheap Chinese c[r]aps, you'd be doing this again in a year or two... if you're lucky.
          Last edited by momaka; 12-19-2017, 08:56 AM.

          Comment


            #6
            Re: Viewsonic vx2235wm colors washed out after power board recapping

            Sorry, they are labeled as 'GMA'
            https://www.badcaps.net/forum/attach...9&d=1513655805
            Never stop learning
            Basic LCD TV and Monitor troubleshooting guides.
            http://www.badcaps.net/forum/showthr...956#post305956

            Voltage Regulator (LDO) testing:
            http://www.badcaps.net/forum/showthr...999#post300999

            Inverter testing using old CFL:
            http://www.badcaps.net/forum/showthr...er+testing+cfl

            Tear down pictures : Hit the ">" Show Albums and stories" on the left side
            http://s807.photobucket.com/user/budm/library/

            TV Factory reset codes listing:
            http://www.badcaps.net/forum/showthread.php?t=24809

            Comment


              #7
              Re: Viewsonic vx2235wm colors washed out after power board recapping

              Hello again,

              GMA1 I get 11.56V.

              Momaka, you are right I installed some spare caps I had from a junk box I had, but not before checking their capacitance and ESR (I have one of those multi function testers that measure caps) making sure they were good. The orange one is brand Sprague and the other is Nichicon.

              What should I test or do next?

              Thank you all!

              Comment


                #8
                Re: Viewsonic vx2235wm colors washed out after power board recapping

                You have GMA1~14 that you need to report all the Voltages to see the pattern.
                Never stop learning
                Basic LCD TV and Monitor troubleshooting guides.
                http://www.badcaps.net/forum/showthr...956#post305956

                Voltage Regulator (LDO) testing:
                http://www.badcaps.net/forum/showthr...999#post300999

                Inverter testing using old CFL:
                http://www.badcaps.net/forum/showthr...er+testing+cfl

                Tear down pictures : Hit the ">" Show Albums and stories" on the left side
                http://s807.photobucket.com/user/budm/library/

                TV Factory reset codes listing:
                http://www.badcaps.net/forum/showthread.php?t=24809

                Comment


                  #9
                  Re: Viewsonic vx2235wm colors washed out after power board recapping

                  Ah ok, sorry I'm a bit slow to understand

                  GMA1 11.56V
                  GMA2 10.86V
                  GMA3 8.98V
                  GMA4 8.57V
                  GMA5 8.28V
                  GMA6 7.65V
                  GMA7 6.43V
                  GMA8 6.13V
                  GMA9 4.93V
                  GMA10 4.16V
                  GMA11 3.75V
                  GMA12 3.21V
                  GMA13 1.24V
                  GMA14 0.122V

                  Tks!

                  Comment


                    #10
                    Re: Viewsonic vx2235wm colors washed out after power board recapping

                    Do these voltages look OK or should I be looking at something else? Please help!

                    Comment


                      #11
                      Re: Viewsonic vx2235wm colors washed out after power board recapping

                      Bump - anyone?

                      Comment


                        #12
                        Re: Viewsonic vx2235wm colors washed out after power board recapping

                        Those voltages look ok, they should be like a ramp, which they are.

                        Comment


                          #13
                          Re: Viewsonic vx2235wm colors washed out after power board recapping

                          Thanks R_J!

                          Can you guide me as to what I should be looking for next? I am totally lost as to what could be causing the washed out picture issue.

                          Also, does that mean that the TCon board looks OK and it could be the main board?

                          Would really like to get this display running normal, as it is my main monitor and my grand daughters are coming for Christmas and will want to play on it. In the meantime, I'm back to my 17" backup display which is pretty small

                          Many thanks for your guidance!
                          Last edited by rddube; 12-20-2017, 09:37 PM.

                          Comment


                            #14
                            Re: Viewsonic vx2235wm colors washed out after power board recapping

                            Originally posted by rddube View Post
                            Ah ok, sorry I'm a bit slow to understand

                            GMA1 11.56V
                            GMA2 10.86V
                            GMA3 8.98V
                            GMA4 8.57V
                            GMA5 8.28V
                            GMA6 7.65V
                            GMA7 6.43V
                            GMA8 6.13V
                            GMA9 4.93V
                            GMA10 4.16V
                            GMA11 3.75V
                            GMA12 3.21V
                            GMA13 1.24V
                            GMA14 0.122V

                            Tks!
                            I do not see anything obvious in those readings so far.
                            Never stop learning
                            Basic LCD TV and Monitor troubleshooting guides.
                            http://www.badcaps.net/forum/showthr...956#post305956

                            Voltage Regulator (LDO) testing:
                            http://www.badcaps.net/forum/showthr...999#post300999

                            Inverter testing using old CFL:
                            http://www.badcaps.net/forum/showthr...er+testing+cfl

                            Tear down pictures : Hit the ">" Show Albums and stories" on the left side
                            http://s807.photobucket.com/user/budm/library/

                            TV Factory reset codes listing:
                            http://www.badcaps.net/forum/showthread.php?t=24809

                            Comment


                              #15
                              Re: Viewsonic vx2235wm colors washed out after power board recapping

                              Originally posted by budm View Post
                              I do not see anything obvious in those readings so far.
                              Thank you Budm. Where do I go from here? What else should I be checking?

                              Comment


                                #16
                                Re: Viewsonic vx2235wm colors washed out after power board recapping

                                QUOTE
                                I should mention that when I powered it back on, it looked fine, but when I did a memory recall (which is factory reset) it came back with the washed out colours.

                                can you alter the color/brightness manually when in the windows screen using the monitors user menu if so does the picture then look ok?
                                Last edited by vinceroger69; 12-21-2017, 04:03 AM.

                                Comment


                                  #17
                                  Re: Viewsonic vx2235wm colors washed out after power board recapping

                                  Originally posted by vinceroger69 View Post
                                  QUOTE
                                  I should mention that when I powered it back on, it looked fine, but when I did a memory recall (which is factory reset) it came back with the washed out colours.

                                  can you alter the color/brightness manually when in the windows screen using the monitors user menu if so does the picture then look ok?
                                  No, when I try to change anything in the menu (which looks fine by the way), there is no change in the Windows image, just plain washed out. When I use the NVidia controls of my graphic card (which works well, the card) then I can change hue, brightness, contrast, etc. but it gives an over brightness type of display, washed out and not much contrast. I tend to think the problem is physical somewhere on the boards. Please help a desperate man, and thank you for all your replies!

                                  Comment


                                    #18
                                    Re: Viewsonic vx2235wm colors washed out after power board recapping

                                    Hmmm.. If the menu colors are okay but only the image from the PC with distorted colors, then the problem likely isn't on the t-con board.

                                    Does the monitor have more than one input? If yes, can you try testing it on the other inputs to see if the problem persists?

                                    Also, what happens if you change the resolution and refresh rate in Windows?

                                    Indeed it appears that the problem is related to a setting in the menu (though I doubt there is a setting to make the monitor this bright, so there may be something more). That said, have you tried a different monitor cable?

                                    Lastly, there should be an "Auto" image-adjustment button on the monitor. Try pressing it to see if that alters the brightness while auto-adjusting and after it is done.

                                    Hopefully all of these questions should help us narrow down the problem.
                                    Last edited by momaka; 12-21-2017, 08:34 AM.

                                    Comment


                                      #19
                                      Re: Viewsonic vx2235wm colors washed out after power board recapping

                                      I've been looking thoroughly through the forums and have not found a solution for a washed out display - seems that no one has been able to fix this type of problem? Should I toss this display out and buy another one, or someone thinks we could find (with a little help from my friends ) the problem?

                                      Comment


                                        #20
                                        Re: Viewsonic vx2235wm colors washed out after power board recapping

                                        I just look at my PC NVIDIA Control panel, there is GAMMA setting that if I set it to Max (2.8) my pictures will be washed out.
                                        Did you try your PC with other monitor yet?
                                        Never stop learning
                                        Basic LCD TV and Monitor troubleshooting guides.
                                        http://www.badcaps.net/forum/showthr...956#post305956

                                        Voltage Regulator (LDO) testing:
                                        http://www.badcaps.net/forum/showthr...999#post300999

                                        Inverter testing using old CFL:
                                        http://www.badcaps.net/forum/showthr...er+testing+cfl

                                        Tear down pictures : Hit the ">" Show Albums and stories" on the left side
                                        http://s807.photobucket.com/user/budm/library/

                                        TV Factory reset codes listing:
                                        http://www.badcaps.net/forum/showthread.php?t=24809

                                        Comment

                                        Working...
                                        X